Abstract

Background: Research shows that cannabis users exhibit deficits in prospective memory and executive function which persist beyond acute intoxication. However, many studies rely on self-reports of memory failures or use laboratory-based measures which may not mimic functional deficits in the real-world. The present study aimed to assess real-world memory functioning. Method: Twenty cannabis-only users and 20 non-illicit drug users were recruited. Participants completed a substance use inventory and a mood scale, followed by a non-immersive virtual reality task assessing prospective memory and executive functioning.The task involves the participant playing the role of an office worker for the day, and performing routine office duties. There are a number of subscales assessing facets ofexecutive function (planning, adaptive thinking, creative thinking, selection, prioritisation) and prospective memory (time-based, event-based and action-based prospective memory).

Results: MANOVA revealed cannabis users performed worse overall on the task, with poor performance on the planning, time-based prospective memory and event-based prospectivememory subscales. In addition, indices of cannabis (length, dose, frequency, total use) were correlated with performance on these 3 subscales.

Conclusions: The present study expands on previously established research, providing support for the cannabis-related deficits in prospective memory and executive functioning, and the role of different aspects of cannabisuse in these deficits.

This is the peer reviewed version of the following article: Montgomery, C., Seddon, A. L., Fisk, J. E., Murphy, P. N. and Jansari, A. (2012), Cannabis-related deficits in real-world memory. Hum. Psychopharmacol. Clin. Exp., 27: 217–225 which has been published in final form at http://dx.doi.org/10.1002/hup.1273 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving